Telephone system



Sept, 2 1924.

H. D. M QPHERSON TELEPHONE SYSTEM Filqd Aug. 15 1921 10 Sheets-Sheet l X OFFIC :3 5

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Sept. 2 1924.

H. D. MacPHERSON TELEPHONE svsrzu //?1/e/7 for: flay/7 49. Ma

iled Aug. 15. 192

S p z. 1924.

1,506,913 H. D. MatPHERSON Tl LE PHONE 5 Y5 'I'EM Filed A 16 1 10 Sheet t a firvenfah flay/7 .0 Mac/998490 Sept. 2. 192

1,506,913 H. D. MHCPHERSON TELEPHONE SYSTBI Filed Augv 15. 1921 10 Sheets-Sheet 9 Patented Sept. 2, 1924.

HUGH D. MAGPHERSON, OF SUMMIT, NEW JERSEY, ASSIGNOR COMPANY, INCORPORATED TELEPHONE SYSTEM.

Application filed August 15, 1921. Serial 1%. 492,229.

To all whom it may concern Be it known that I, HUGH D. MAGBHER- soN, a citizen of the United States, residing at Summit, in the county of Union, State of New Jersey, have invented certain new and useful Improvements in Telephone Systems, of which. the following is a full, clear, concise, and exact description.

This invention relates to improvements in telephone systems and has particular reference to a system wherein the signals for a plurality of toll lines extending between widely separated oflices are transmitted over a signaling path common to said toll lines.

It has been hertofore proposed to employ a signaling path common to a. plurality of toll lines and extending between distant offices with means at each end of said path for transmitting thereover supervisory signals characteristic of each individual line and incident to the establishment and release of a connection over said line. In systems of this character it has been necessary for the outward operator at an initiating office to communicate with the inward operator at a distant or incoming oliice to verbally inform her of the number of the wanted line. whereupon said inward operator proceeds to complete the connection. usually through a. toll switching operator.

An object of the present invention is to provide a system of the above character wherein the necessity of the outward operator verbally communicating the number of the wanted line to the incoming operator is eliminated.

In accordance with this object use is preferably made of a call indicator positioned before the incoming operator and operable. in response to the registration of a call by the outward operator and consequent actua+ tion of signal transmitting and receiving means, to indicate the number ofthe has wanted, whereupon the. incoming operaztor may then proceed to complete-the GBB8G- tion. 1 I

Another object is to provide means whereby the signals individual to each line, which are employed for supervising a connection over sald line and those for controlling the operation of the call indicator, may be trans mitted over the same signaling path which is common to a plurality of lines.

Other objects will appear in the course of the following description when taken in connection with the accompanying drawings, Figs. 1 to 10 ofwhich, when amdnged in acordance with Fig. 11, illustrate a pre ferred embodiment of the inventive idea? General description of operation.

Briefly, the invention comprises a plurality of toll lines, similar to the line L, extending between an outward operator at one office and an incoming operator at a distant office. The outward operator is provided with a number of cordcir'cuits, sl cli as indicated at A, any one"oi=whichniay teemployed to connects callingsnbscribers line with one of the toll lines. At the outward operators position there is provided a set of keys operable to register the oflice, numerical and station designations of a wanted line. 'lhese keys may be of any preferred type well known in the art and upon actuation thereof by the outward operator certain re; lays in the cord register shown in Fig. 1, carresponding to the operated keys, are energized to prepare circuits for the energization of similar relays in the line register illustrated in Figs. 5 and 6. After registering the number of the wanted line on the cord register. the outward o orator then connects the cord A with an id e toll line L, whereupon certain operations take place which result in the connection oi the cord and line registers and the eoergization of relays in the latter in accordance with tite condition of relays in the former. T he codes for the various 'oifice; numerical and station designations of the called line, which consist otimplilses of different polarities determined 333? the condition of the line register relays, are now stored in the line register and await the transmission of supervisory impulses to the distant office 'which light a guard lam therea-t individual to the toll line talten'for use, to inform tho inoorning operator that a call is awaiting attention on said line, These supervisory impulses, which are individual to 1 the: litte are transmitted immediately upon connection of "the cord A with the lme L and while the line register relays are heing operated. V 'E The incomingoperator, in response to the actuation of the signal'for lineL, operates an assignmentkey which results in the trans; mission of a code of impulses to the outward office followed by a repetition ofthis code from the outward to the inward cites to T0 wns'rnnn on NEW YORK. iv. in, A CORPORATION or NEW roux.

associate the incoming operatorls call indicator iv iththe dine register andthe'common signaling path over which all impulses are transmitted. Eight series of code impulses are now transmitted in accordance with the condition of the register relays in the line register, these series corresponding to the three office, four numerical and one station designations of the wanted line. In response to these series of impulses the call. indicator before the incoming operator is actuated to display. by means of lamps, the number of the; called line.

The incoming operator now secures an assignment of a toll switching trunk, such as H, from the toll switching operator and at the same time informs her of the number wanted. The latter operator then connects the toll switching trunk with the called subscribers line. The incoming operator connects the line L with the toll switching trunk which results in the release of the call indicator and the transmission of the individual code of line L to the outward ofice to light a guard lamp thcreat in response to which the outward opera-tor actuates the ringing key to signal the wanted subscriber. hen the call is answered a code of impulses is again transmitted to the outward office to extinguish the guard lamp after which the outward operator no longer actuates the ringing key.

At the termination of a conversation the release of the connection is effected by the called subscriber replacing his receiver upon its switch hook. whereupon a. code of impulses is transmitted to the outward oilice to again light the guard lamp to give the outward operator the disconnect signal. This operator then disconnects the cord circuit A from the toll line L which causes the transmission of a code of im ulses to the inward office to simultaneously light the guard lamps before the incoming and toll switching operators who then restore the circuit to normal by disconnecting the line L from the trunk H and said trunk from the called subscribers substation circuit, respectively. At any time during the conversation the called subscriber may recall the outward operator by moving the switch hook up and down. Codes of impulses are transmitted fromthe inward to the outward ofiice and theiiireception at the latter office causes apparatus to function to flash the guard lamp before the outward operator who thereupon connects her head set to the line.

i If at the time of establishing a call the toll switching operator finds the'wanted line busy,she inserts the plug of trunk H into a busy flash jack. This operation causes the guard lamp before the outward operator to flash and upon connecting her head set to the line she receives a distinctive tone indieating a busy condition on the line wanted.

The release of the connection is then eflt'ected as previously referred to. e a

Detailed description of operation.

It is believed that the invention will now be fully understood from the following detailed description of the operation of establishing a connection from an outgoing operator at one office over an idle toll line L to a called subscriber, whose substation is shown in Fig. 7 and located in a distant office. A calling subscriber may be connected to the outgoing operator in any manner well-known in the art. Since this operation forms no part of the present invention, the apparatus for making this connection is not shown in its entirety, only a portion of the outgoing operators cord circuit A, which is employed to connect to the calling subscribers line, being illustrated.

Operator registers number of called line in cord register circuit.

Upon ascertaining the number of the called subscribers line from the calling subscriber, the outgoing operator first proceeds to set up this number on the cord circuit register illustrated in Fi s. 1 and 2. It will be assumed that the OlTlCB designation of the wanted line is represented by the letters WAL and the station designation of said line by the letter M. The register relays are arranged in groups and those for the office designations are indicated by the numerals 114 to 125, while relays for station designations are indicated by the numerals 126 to 129. The relays of the register representing the number digits of called lines have been omitted for purposes of economy in space and description, but it will be understood that these number relays operate in the same manner as the oflice and station relays. The operator first depresses the key 9. which corresponds to the first letter of the ollice designation, whereupon an operating circuit is established for register relay 116 of the first group, which circuit extends from ground through the winding of relay 100, the right hand alternate contact of lie 9, the right hand normal contact of key 6, the left hand normal contact of key 5. the lower normal contact of the transfer relay 102 individual to the first group of register relays, and the lower winding of relay 116 to grounded battery. An operating circuit is also established for relay 117 of the firsl 7 cup, which circuit extends from ground. through the winding of relay 100, left hand alternate contact of key 9, theupper normal contact of relay 102, and the lower winding of relay 117 to grounded battery. Relay 100 is also energized in either of these circuits, and in closing its contact establishes a circuit for relay 103 extending from grounded battery through the winding of said relay, the lower normal contact of relay 101, and thence to ground through the contact of relay 100; Relay 103 energizes to close acireu t through its contact, the windings of relay-s 102 and 101 in series, and the contactof relay 113 to ground. Relays 101 and 102 do not energize in this circuit since they are short-circu ted by the ground conreacted to contact of relay 100 and extending through the lower normal contact of re lay 101, and contact of relay 103. Relays 116 and 117, upon energization, are locked up through their upper windings and contacts to ground at the contact of relay 113. The operator non releases the key 9. whereu-pon relay 100 releases to remove the shortcireuit from the windings 101 and 102, and these relays thereupon energize over the circuit extending to ground at the relay 113 to transfer the conductors extending from the various keys of the operators set to the normal contacts of the second group of tr'ansfier relays 10 1 and 105. The operator next depresses key 2 and again establishes a circuit'for relay 100 and register relay 119 of the second group, said circuit extending from g'round, throngh the Winding of relay 100; theleft hand alternate contact of key 2; the lower alternate contact of relay 101, the middle normal contact of relay 104 and the lower Winding of relay 119 to grounded battery. Relays 100 and 119 encrgize, and the latter'relay locks through its upper Winding and contact to ground at the contact of relay 113. The energizat'fon of relay 100 new establishes a circuit for relay 106, extending from grounded battery, through the winding of said relay, the lower normal contact of relay 104:, the upper alternate contact of relay 102 and the con-- tact of relay 100 to ground; Relay 106 energizes and through its con-tact closesa circuit in series. through the windingsof relays 104 and 105 to ground at the contact of relay 113. but, as befiore described in counectiozi with relays 1.01 and 102. relays 104 and 105 are short-'circuited as long as relay 100 remains operated. Uponthe release of key 2, relay 100 releases to remove this shortcircuit; and relays 104 and 105 thereupon energize; Relay lfifirlocks up in the circuit described for relaysIOr-l and 105. The oondoctors leading from the keyboand are new extended through theralternate contacts of transfer relays 101, 102 and 104 105 to the normal contacts of relays 107 and 108. Upon the depression of the key corre spending to the third letter of the oflice des ignation; relays 100 and 124 are operated over a circuit extending from ground, through the Winding'of relay 100,- the left hand alternate contact of 5, the lower alternate contact of relays 102 and 105,- the lower normal contact of relay 108 and the lower winding of relay 124 to battery; Re

lays 100 and 124 energize; and the latter relay locks through its upper contact to ground at the contact of relay 113. The

energization of relay 100 establishes a aircuit for relay 109 extending from grounded battery through the winding of relay 109, the lower normal contact of relay 107, the upper alternate contacts of relays 105 and 102, and the contact of relay 100 to ground. The energization of relay 109 establishes a circuit for relays 108 and 107 in series to ground at the contact of relay 113, but said relays 108 and 107, as before described in connection with the other transfer relays, are short-circuited until relay 100 releases; whereupon said relays energize in the lock: ing circuit for relay 109. The setting up oi the ofiice designation is now completed, and the operator then proceeds to depress'ke 5 corresponding to" the number digits of -t 1e called line. In response to the successive actuation of these keys, the number register relays and correspondin transfer relays which have been omitted rom the drawing, are operated in the same manner as described for the cities register relays. The operator then completes'the registration of the called line by actuating the key 6; which corresponds to the station designationof said line, whereupon relays 100, 126 and 128 will operate over circuit which will be oh vious from an understanding of the description of operation of the other register relays. Relay 112 also energizes upon the operation of relay 100 over a circuit extending through the lower normalcontact of relay 110 and the upper alternate contacts of re lays 108, 105 and 102. ,When rela 100 releases in response to the restoration of the key 6,' relays 110 and 111 are energized in series with relay 112." The operation of transfer relay 111 connects battery through its alternate contact to the winding of relay 200,;but this relay does not energize until the line register (Fig. 6) and apparatus as sociated'with the toll line are in condition to receive impulses from the cord register. which occurs after the plug 203 of the cord circuit- A isinserted into the jack 3'00 rat-the idletollline L as will be more; fully described hereinafter. Register relays corre spondin to digits in the wanted line are now operated: and locked, and transfer re la'ys individual to the groups of register re lays are also energized.

Should the operator at any time desire to erase the registration made, she may do so by actuating the. wipe-out key 180. which closes ain 'obyious circuit forielay 113. The 0' oration (If this relay removesgroundfnom fi contact thereoffan d thus opens the holding circuits for such transfer relays as have been operated and the locking circuits of the register relays and of relays individual t said, trans er relay Theapparaws s thereby restored to normal, and the operator may then proceed to again register the called number.

Operator connects 00ml circuit A to idle toll line L.

The operator having completed. the registration of the called line, inserts aplug 203 of the cord circuit A into jack 300, whereupon a circuit is established for relays 201 and 301, extending from grounded battery, through the windings of relays 201 and 202. sleeve contacts of plug 203 and jack 30 and winding of relay 301 to ground. Relays 201 and 301 energize in this circuit, but relay 202 being marginal oes not operate at this time. The energiza ion of relay 301 establishes an obvious circuit for the busy signal magnet 302.. which operates to indicate the busy condition of the toll line L. The operation of relay 201 closes an obvious energizing circuit for relay 204, which disconnects the tip of the cord from the operators busy test circuit and closes the tip circuit through the front contact of relay 204. The cord circuit register now awaits the condition previously referred to in the line apparatus and re ister.

The insertion o the plug 203 into jack 300 and consequent energization of relay 301 establishes an obvious energizing circuitfor relay 304. The opening of the normal contact of this relay removes ground from the terminal individual to the trunk line L, over which the wiper 400 of the rotary switch O passes. This switch is common to all of the toll lines in the group in which line L is located and is operated, as will presently appear, to engage wipers 400, 401, 402, 403, 404, 405 and 406 with terminals associated with the selected toll line. A plurality of link circuits, one of which is shown at D, are associated with switches such as G, and are employed for connecting the line circuit to the line register shown in Figs. 5 and 6 through wipers of a rotary switch E, which operates to preselect an idle line register. An idle link circuit D is preselected by means of a rotary switch Ff common to a group of links serving all of the toll lines. Vipers 407 and 408 of said switch F engage terminals individual to said idle link when a toll line in a group is taken for use. The energization of relay 304 also estab lishes a circuit from ground, through the right hand alternate contact of relay 304, the contact of relay 307, conductor 308, common to all the toll lines in the group, and winding of relay 409 to grounded battery. Relay 409 energizes and remains in this condition until switch 0 has been operated to step its wipers to engage the terminals individual to the line L. Upon energization of relay 409, a circuit is established from ground, through the contact of this relay,

wiper 407 and the preselected terminal engaged thereby, wiper 400 in its normal position, the normal contact of relay 410 and the contact and winding of stepping magnet 411 to grounded battery. A circuit is also closed through the windi'ngof relay 410, but this relay is shunted by the first described circuit until wipers of switch 0 have engaged the terminals of the toll line. Another circuit is established for relay 413 by the energization of relay 409, extending from grounded battery, through the winding of this relay, wiper 407, and contact of relay 409 to ground; The effect of the latter circuit wi l presently be described. The circuit described for magnet 41]. causes the switch C to step its wipers from their'normal positions and engage terminals indi' vidual to other toll lines. As long as the wiper 400 engages the terminal individual to an idle line, ground will be found upon this terminal through the normal contact of relay 304 of said idle line, and circuits will beestablished to continue the operation of stepping magnet 411. It is to be here noted that if two toll lines in the same group are simultaneously taken for use, the switch 0 will stop up on the terminals of the first line encountered, and the second toll line must await the preselection of another link circuit similar to D and associated with a different switch 0. Upon engagement of wiper 400 with the terminal to which ground has been removed by the energization of relay 304, a circuit is no lon or established for magnet 411, and the switch thereupon comes to rest upon the terminals individual to the toll line L. The circuit through magnet 411 and winding of relay 410 to ground at the contact of relay 409 now becomes effective to energize relay 410. but magnet 411 will not energize in series with this relay. The energization of relay 410 completes an energizing circuit for relays 307 and 412', extending from grounded battery. through winding of relay 307, the left hand alternate contact of relay 304, wiper 400 and terminal engaged thereby, the alternate contact of relay 410, and the winding of relay 412 to ground. The energizationof relay 307 in this circuit opens the operating circuit for relay 409, which thereupon releases to open the energizing circnits' for relays 410 and 413, but before relay 409' can release, the energizaticn of relay 412 establishes. through its middle contact, substitute holding circuits for relays 410 and 413. The operation of relay 412 also closes a circuit for stepping magnet 414 of switch F, through the wiper 408 thereof to step said wipers from the terminals individual to the busy link circuit, until wiper 408 encounters a terminal free from ground, whereu on switch F comes to rest, and another link circuit is thereupon preselected. At the time reiay 413 energized, relay 501 opcr ates in a circuit extending frezn ground through the contact of relay 413, the winding of relay 501 and the contact and winding of stepping magnet 500 to grounded battery. The stepping magnet being in series with relay 501, does not operate in this circuit and the Wipers of switch E remain on the terminals of the preselected register. The energization of relay 501 establishes a circuit extending from ground, through the alternate contact of this relay, the wiper 502 and terminal engaged thereb and the left hand winding of relay 510 to grounded battery. Relay 510 energizes to close an obvious circuit for relay 509. The closure of the middle contact of this relay provides a busy test so that the busy line register Will not be taken for use by a switch similar to switch E throu h another linkcircuit. T he operation of re ay 509 also closes a circuit extending from ground, through the left hand contact of relay 509, normal contact of slow release relay 511, wiper 50? and tier urinal engaged thereby, the left hand contact of relay 412 which is now opera-ted, wiper 405 of switch C and terminal engaged thereby, the right hand normal contact of relay 809, and the winding of relay 303 to grounded battery, causing the operation of the latter relay.

The line circuit and register are now in condition to receive impulses from the cord register circuit to operate the storing and transmitting relays of said line. The operation of relay 303 establishes parallel circuits through windings ofrelays 305 and 309 to ground at the contact of relay 301, but relays 305 and 309 are short circuited by the ground from the left hand contact of relay 509, which causes the energiza-tion of relay 303, and relays 305 and 309 therefore do not operate at this time. The operation of relay .303 also closes a circuit extending from ground, through the normal contact of relay 305, the right hand contact of relay 303, resistance 306, the sleeve terminals of jack 300 and plug203, and windings of relays 202 and 201 in series to grounded battery. Marginal relay 202 operates in this circuit, and the closure of the contact of this relay establishes an obvious encr izing circuit for relay 205. The latter re ay thereupon locks through its inner right hand contact to ground at the contact of relay 201. V The operation of relay 205 closes the circuit ex.- tending from ground, through the outer left hand contact of said relay, the left hand normal. contact of relay 206, and the winding of relay 207 to grounded battery. Relay 207 operates to connect the tip and ring conductors of the cord circuitAv to the conductors 208 and 209, which lead to contacts of relay 210. Conductors 208 and 200 are common to the arieuscord pitcujfi similar to the card 5A at the pntward operators position, The energization of relay 205 connects ground at the eontact of relay 201, through the outer right hand (mietact of relay 205, the inner right hand nor:- mal contact of relay 206, to the winding of relay 200. Battery havin previeusly been connected to relay 200 lhrough tile alternate contact of transfer relay 11 1, the relay 200 new energizes. Lanrp 2111s also lighted at this time to indicate to flm-ont ward operator that the call which waer 4 istered on the various register relays is n bein transmitted to the line register.

A ter the operation of relay 200, a cia cuit is closed for relay 212, llowing the engagement of the contact of the interns t'er 213 with a grounded segment thereei, w ich circuit extends from grounded battery, through the winding of relay 2112, 110mm. contact of relay 21 4, and the of lay 200 to ground throiigh'the initemplier 213. Relay 212 energizes, and opera tion thereof establishes a circuit for role? 214, extending from grounded h A through the winding and acontact of relay 212, winding of relay 214, the inner I'i ht hand normal contact of relay 206, the outer right hand contact of relay 205, and the contact of relay 201 to gnonnl. Relay 214 is short-circuited through its con: tact, and the .contactnf hole}? 212 as lbngifls the brush of interrn tar 213 1; grounded segment. W jen a non-grounded segment is reached, relay 214: energizes, and relay 212 locks in the energizing circuit of relay 214. hVhen the brush of interrupter 213 again r aches a ground d segment, ground is extended through the alternate contact of relay 214:, the right hand normal contact of relay 215, and'tjhe windingijoi relay 210 to grounded. battery. BQ ziyz-filtl energizes to connect the conduotmitfilfi and 209 to the wipers 216 and 221K of, SWifioh B, A th s m im a 1a 21.59 issuergized, a ,circuit is establish {oaths ,sgepping magnet 218 of switch B, amending from grounded battery, through the ing of this magnet, the left hand normal contact of relay 215, and from thence to ground over .the circuit described feg g'ejay 1 e s pp n ma n v52.15 n giz but the step ing pawl thereoi is sei ggranged that t e, wipers of switch 15 he moved until the circuit ion-thee magnet is opened and Said a 1 Transfer of record from rear ange line regt'sterf In the description of operation of the cord circuit register, it will be recalled register relays 116 and 117 oi the ggoup were e d, anire ys g t and; 115m said group remained inert.

can

right with wipers .216 and 217 of Bin their first positions, a circuit is eetablishedzfrom ground, through the resistance 131 at relay 115, the normal contact of relay, wiper 216 and terminal engaged'thereb the left hand contact of relay'i210, con uctor 208, left hand alternate contact oi rela 207, the alternate contact oi .rela. .204, t a tip contacts of pin 203 and jac 300, the inner left hand norma contacts-cf relays 305 and 309, wipers 406 and 508 and terminals engaged thereby, win-d- 77 .ot relay .512,the middle normal contact h i transfer relay 600, and the right hand windingof register. relay 602 to ounded battery. Relay 512 operates in this circuit, but due to the inclusion of the resistance 131 therein, relay 602 will not operate. Inasmuch as relay 114 is not operated, the ground at its lower contact will not be extendedthrough wiper 217 and condurto-r 209 to the ring contacts of the plug and jack 203, and 300, and from thence to the winding of r relay 603, and this latter relay will t erefore remain inert. The energization ofrelay .512 establishes a circuit or relay 601, extending from grounded hattery, through the winding of relay 601, the upper normal contact of relay 600, and the contact of relay 512 to ground. Relay 601 operates, and through its contact closes a circuit through the winding of relay 600, and the right hand contact of relay 509 to ound, but relay 600 does not energize since it iSShQIlB-CllfllllbE/(l by the ground at relay 512, through the upper normal contact of relay 600, and the contact of relay 601. When the brush of interrupter 213 next engages an ungrounded se ent, relays 210 an 512 and magnet 218 re ease. The release of relay 512 removes the short-circuit for relay 600, which thereupon energizes and locksin series with relay 601'. The restoration'of the magnet 218 steps the wipers of switch B to position 2.

' When the brush of interrupter 213 again connects ground to the contact of relay 200, relay 210 and-magnet 218 again operate. Register relays 116 and 117 are now associated, respectively, with the tip and ring contacts of plug 203 through wipers 216 and 217 in position 2. The operation of relay 116 establishes a circuit from ground, through the lower alternate contact of relay 1'16, wiper 216, and from thence over the previously described circuit through the tip contacts of plug 203 and jack 300 as far as the middle normal contact of transfer relay 600. This relay being now energized, the circuit is extended through the middle alternatcontact of said relay, the middle noranal contact of transfer relay 604, and the hand winding of register relay 606 to grounded battery.- Since the resistance at relay 116 is llihli'lclflfl ed in this circuit,

both relays 512 and 606 will operate. Relay 606 locks through its left hand winding and contact to ground at the right hand contact of relay 509. It will be recalled that relay 117 is also operated, and a circuit will therefore. be established extending from ground, through the lower contact of relay 117, wiper 217 in position 2, the right hand contact of relay .210, conductor 209, right hand alternate contact of relay 207, ring contacts of plug 203 and jack 300, outer left hand normal contacts of relays 305 and 309, wipers 404 and 506, the lower alternate contact of transfer relay 600, the lower normal contact of relay 604, and the winding of relay 607 to grounded battery. Relay 607 energizes and looks through its left hand contact to ground at the right hand contact of relay 509. The operation of relay 512 in the circuit for relay 606 closes a circuit for relay 605 extending from grounded battery, through the winding of relay 605, the upper normal contact of relay 604, the upper alternate contact of relay 600, and contact of relay 512 to ground. Relay 605 energizes and locks in a circuit through its winding and contact, the winding of relay 604, and from thence to ground at the right hand contact of relay 509. Relay 604 does not operate in this circuit due to its being shunted by the ground at relay 512 while this relay remains. operated. Upon the next release of relay 512 at the time'that the brush of interrupter 213 next engages a non-grounded segment, the short-circuit. for relay 604 is removed, and this relay operates in Series with relay, 605. It will thus be seen that the engagement oi wipers 216 and 217 with two associated contacts is necessary to convey the conditions existing at the lower contacts of the cord register relays in the first group. Upon the engagement of the brush of interrupter 213 with the next nongrounded segment, which results in the second release of relay 512 to remove the shortcircuit from relay 604, relay 210 and magnet 218 also release, whereupon switch B is stepped to engage its wipers with the third contacts.

Thesecond group of cord register relays, of which relay 119 is energized, are now associated with the conductors 208 and 209. The operation of relay 119 disconnects resistance'133 from the third terminal, upon which Wiper 216 is now resting. Ground is connected directly to the alternate contact of relay 119 through wiper 216, and from thence, after relay 210 is again energized in response to the engagement of the brush of interrupter 213 with a grounded segment, over the previously described circuit through the tip contacts of the plug and jack, as far as the 'middle normal contact of relay 604. This relay now being energized, the circuit is extended through the middle alternate insane contact of relay 604, the middle normal contact of relay 608, and the right hand Winding of relay 610 to grounded battery. Relays 610 and 512 Operate in this circuit, and the former locks through its left hand contact to ground at the right hand contact of rela 509. The operation of relay 512 establis es a circuit for relay 609, through the u or alternate contacts of relays 600 and G i, and the normal contact oi reia 608. Relay 609 energizes and looks through its contact and the winding of relay 608 to ground at the right hand contact of relay 509. Relay 608 does not energize in this circuit for the same reason referred to respect to relays 600 and 604. Inasmuch as relay 118 of the second group of cord register relays is not operated, the ground at the lower contact of said relay will not be extended through wiper 217 over the ring contacts of the plug and jack to relay 611, and this latter relay'w ill therefore remain inert. At the next interruption of the ground connection at interrupter 213, relay 210 and magnet 218 again release, and wipers of switch B are stepped to position 4. The relays 120 and 121 are now associated with wipers 216 and 217 Relay 512 again releases to remove the short circuit for relay 608, which energizes in series with rela. 609.

pen the next operation of relay 210 and magnet 218 in response to the continued rotation of inter u ter 213, a circuit is established from ground through the resistance 134, the normal contact of relay 120, wiper 216 in position 4, and from thence over the previously described circuit through the tip contacts of the lug and jack Winding of relay 512, middle alternate contacts of relays 600, 604 and 608, middle normal contact of relay 612, and the right hand winding of relay 614 to grounded battery; Relay 614 is not energized in this circu t due to the inclusion of the resistance l d l, but relay 512 energizes to establish an energizing circuit for relay 613, through. the upper alternate contacts of relays 600,604.- and 608, and upper normal contact of relay 612. Relay 613 looks in series with the winding of relay 612, but the latter relay does not energize due to the short-circuit established by relay 512. "Relay121 is energized. and therefore groundwill not be connected to the ring contact of the lh-g and jack. so that relay 615'will fa1l to operate. The interrupter 213 next causes the release of relays 210 and"512,'-and the magnet 218. with the result that the Wipers of switch B are stepped to position 5 to associate the third group of cord register relays with wipers 216 and 217. The opera tion of successively associating "the various groups of cord register relays with the mechanism of the line register causes the operation of the remaining transfer relays 616, 620, 624 and 62-8 and associated'relays 617, 621., 625 and 629 in the same manner as described in connection with other similar relays. Certain combinations of register relays 618, 619, 622, 623, etc, and register relay's'individual to the number digits which have been omitted from the showing, are also operated or remain inert in accordance with the condition of relays in corresponding groups in the cord register circuit. Bearing in mind that relay 124 of the third group, and relays 126 and 128 of the last group are energized, it will be apparent that relays 622, 627 and 630 will energize and lock, and relays 618, 619, 623, 626 and 631 will remain inert.

After the potentials at the last group of cord register relays have been transmitted to the line register, and relays 629 and 630 have operated, relays 210 and 512 and magnet 218 release due to the engagement of the brush of interrupter 213 with a non-ground ed segment, and relay 628 energizes in re sponse to the release of relay 512. The release of magnet 218 new steps the Wipers of switch B to position 17, and inasmuch as the seventeenth and succeeding positions of wipers 216 and 217 are not connected to any of the cord register relays, it will be obvious that the operation of line register relays will cease. Upon the operation of relay 629, a circuit is established extending from grounded battery, through the wind ing and contact of relay 629, the winding of slow release relay 511, and the ri ht hand contact of relay 509 to ground. l elay 511 is operated in this circuit. and in opening its normal contact, removes ground from the winding of relay 303. It will be recalled that this ground, through the normal contact of relay #11, short-circuited relaiys1305 and 309, while relay =303 was oper- Upon the'removal this ground, re- Bays'305'and309 operate in parallel from ground at the contact of relay 301, through the inner contact and winding of relay 303 to grounded battery." Relay 303 therefore remains energized, and the operation of re lay 305 connects the tip and ring conductors of the cord circuit A to the toll line L. The operation of relay 30,) also removes the ground connection 111 its normal ,flon nacathro gh resistasee 306, whereupon relay'202; which was energized through this resistance, 'is' released; The release 9f 202 opens the or al energizing circuit ldr relay 205, but t is? relay is] now locifd through its'dfinenright hand contact to ground at the contact of relay 201.

At-the time the wi mrs of switch B were stepped to position 17, a circuit was estab lished for relay 215, extending from grounded battery, through the winding of relay 215, and wiper 219 in position "17 to ground. Relay 215 energizes in this circuit, and in so doing establish% a self-interrupting circuit for the stepping magnet 218, extending from grounded battery, through the winding and contact of said magnet, the left hand alternate contact of relay 215, and wiper 219 to ground. Magnet 218 operates and releases to step the wipers of switch B over the succeeding ter minals thereof until said wipers have reached their normal positions where ground is no longer found upon the terminal engaged by wiper 219. Magnet 218 will then cease to operate, and the wipers of the switch will be brought to rest. The movement of wiper 220 to position 17 closes an obvious energizing circuit for relay 113 of the cord register, and this relay in operating disconnects ground from its normal contact, to open the locking and holding circuits of the transfer and register relays of the cord register, whereupon all of these relays are restored to normal. and the regis ter is then in condition for another opera tion.

The energizati-on of relay 215 also establishes a circuit for relay 206 extending from grounded battery through the winding and continuity contacts of relay 206, the inner left hand contact of relay 205, and the inner right hand contact of relay 215 to ground. Relay 206 energizes and looks through its left hand alternate contact, the outer right hand contact of relay 205, and the contact of relay 201 to ground. In opening its left hand normal contact, relay 206 causes the release of relay 207 to connect the cord circuit A through normal contacts of relay 207 and alternate contact of relay 204 to the toll line L. The opening of the inner right hand contact of relay 206 breaks the holding circuit through the windings of relays 212 and 214, andthese relays thereupon restore to normal. Relay 200 also releases, and lamp 211 is extinguished due to the release of transfer relay 111 and energization of relay 206. Relays 201, 204, 205 and 206 of the apparatus individual to cord circuit A are now operated and remain in this condition throughout the duration of the call.

The operation of relay 305, as previously described, closes an obvious energizing circuit for relay 310. This relay, in operating, establishes an energizing circuit for relay 311 extending from grounded battery, through the normal contact of differential relay 312, winding of relay 311 and from thence to ground at the alternate contact of relay 310. The energization of rela 311 disconnects the left-hand winding of" iflerential relay 320 from the conductor 322, to prevent:v the operation of said relay while relay 311 is operated. Relay 310 also closes a circuit extending from oundthrough the alternate contact thereo the right-hand normalcontactsof relays 313 and 314, the winding of relay 315, the contact of relay 316 and the left-hand normal contact of relay 317 to grounded battery. Relay 315 energizes in this circuit and temporarily locks through its inner left-hand contact. The energization of relay 315 establishes an obvious energizing circuit for relay 318 and this relay then looks through its left-hand contact to ground at the inner leftrhand normal contact of relay 314. By the closure of the inner right-hand contact of relay 315, ground is extended from thence through the outer left-hand contact of relay 314, t e outer right-hand contact of relay 319, to a terminal individual to toll line L in the bank of switch F over which the wiper 416 passes.

The switch F is common to all the toll lines in the group in which the toll line L is located and is designed to connect the apparatus of Fig. 3 and of the line register to that associated with the sending distributor SD. This sending distributor is preferably of a type similar to distributors employed in printing telegraphy and is operated in synchronism with a receivin distributor Bl), (Fig. 8) located at a distant oflice whereby impulses from the outgoing office may be transmitted to the distant oflice to indicate at the latter ofiioe the particular toll line which has been taken for use. In accordance with the present invention, the distributors are also employed for transmitting the code set up on the line register to the distant oflice to operate the call indicator located at said distant oflice before the incoming operator.

Association of signaling apparatus with se lected toll Zine.

Referring again to the operation of relay 315, the closure of the outer right-hand con tact 01: this relay establishes a circuit from ground through said contact, the inner right-hand contact of relay 319 and the winding of relay 415 to grounded battery. Relay 415 operates and in so doing, establishes a self-interrupting circuit for the stepping magnet 417 of the switch F extending from grounded battery through the winding and contact of said magnet, the normal rontact'of relay 418 and the contacts of relays 419 and 415 to ground Magnet 41? operates to step the wipers 416 and 420 to 426 of the switch to seek associated terminals individual to the toll line L. This operation continues as long as the Wiper 416 doesnot encounter ground upon an associated terminal, but as soon as wiper 416 engages the terminal to which ground is connected by the energization of relay 315. a circuit is established for relay 418 from grounded battery, through the left-hand winding of relay 418, and the wiper 416 to anaemia viduah to line Li With the wipers of the switch F engaging-terminals individual to line L. the apparatus is in condition to transmit-arcade of impulses through the distributor SD tothe receiving distributor R1) over a common'conductor P terminating in windings of polar relays 428 and 828 This code, in the present arrangement consists of five impulses which are successively trans mitted and which differ with respect to their polarities. Each toll line has a different combination of positive and negative polarities to distinguish the same. line L being. represented by a I code consisting of two positivc impulsesyar negative impulse;

a positive impulse and then" 'a 'negative impulse. The first furot "thesepotentials are connected to the normal- 7 contacts of the transfer relays 429 to 432 which operate in a manner'to appear in thecourse of the de- SCIlPtiOiL' after the toll line code has been transmitted; toconnect the line register with the sending distributor: whereby the impulses fromsaid line register are passed over the common-signaling path P to operate the proper lamps in the call indicator of Fig. 10.

Upon the operation of'relay 418, as prcviously described, a circuit is established for the start magnet 433 of the sending distributor. said circuit extending from grounded battery through the lamp 434, ring 435 of lhesending distributor; brush arm 436. start segment 43?; the outer right-hand contact of relay 418 and the Winding of "magnet 433- to ground 3 Thb magnet 433 is energized and the lamp 434 lighted in this circuit. lighting of the lamp 434 -indicates that'the distributor is in use.- The energization of magnet- 433 releases the brush arm 436 of the sending distributor which thereupon makes acomplete revolution As soon as the brush arm 436 passes beyond the start segment 4-37; the energizing circuit for the start mega I net 433ds opened land the armature of said; magnet is thereby moved to aposition=:izr"

the path ofrotation oi the brush-ar1n=436 so that this arm= engages and is stopped by said armature upon completing itsrevolu 1 tion.

Upon engagement of the brush-arm 436 with the segment 438 at the beginnin of its revolution. a circuit-is established rom positive pole of battery through the segment 438, brush arm 43%. rirrg439and from thence over one path through thelower Winding of polar relay 428 and the artifis (rial line to ground and over another path through the upper' windi'ngof relay 428, commonconducto'r P, both windings of polar" relay 828* and" the: artificial lineto The I ground, The closure of this circuit has no effect upon the polar relay 428, but causes relay R28 to close its upper contact. A circuit is thereby closed from grounded battery through the upper contact of relay 828, the

segment 8000f the receiving distributor RD, brush arm 801V thereof, segment 802 and the Winding of start magnet 803 to ground. The magnet 803 operates to releasebrush arm 801 so that the same will make a complete revolution in synchronism with the sending distributor SD. During the rotation of brush arms 436 and 801, the impulses are transmitted over the common conductor P in accordance with the code designa tion of toll line L. In order that the transmitted code combinations may be translateol; into suitahlesignals fob appropriate toll lines, the inventionpreterahly includes the=provision of receiviingwa-pparatus associated with the receiving distributor RD which is selectively responsive to the transmitted code combinations to cause the opera tion of signals individual to thevarious toll lines. Th'ezselective receiving apparatus, as herein shown includes a pluralityof locking rclays'804 to 809; thelocking circuits of which are con trolledi rib-y; a common r lay 810... The apparatnsafurther includes a 19 known in the signaling art; the relays of pyramid relay combination of n type Well this combination; being indicated by the numerals'811 to 825. In accordance with the code signaling impulses transmitted, the apparatus including the locking and pyramid relays responds to provide-apath through contacts of saidrelays over which the sig nal individual to the toll Nine? selected I is i operated; 7 i V Retumi-ng now to the operationeof send:

in'g? distributor SD, when theiibrush arm;

extending from grounded; battery through.

the ECOIItfiGt of relay 441 the wiper 420' and the 'terminal engaged thereby the normal contact ofirelay 321 and the Vwindin of relay 317 to ground In energizing,re ayf317, disconnects-battery through its outer normal contact from the locking circuit of relay 315*and this relay thereupon releases. The operation'of relay- 317 establishes an energizing cireuit for slow-release relay 313 1 extending' fro-m' grounded hatter-y through" the alternate contact of relayj317, righthan-dalternate contact- 0f relay 318, which is locked at this time, the Windingof-relay 313 andwthe inner left-hand normal contact otrela y3i4to ground Relay -31 3 energizea and locks through its inner left-hand alternate contact and winding to ground at the last-mentioned contact of relay 314. The deenergization of relay 315 removes ground from the winding of relay 415 whici then. releases and also removes ground from the terminal engaged by wiper 416 to open the energizing circuit of relay 418. The latter relay, however, is maintained energized through a lockin circuit extending from ground through tie right-hand winding of said relay, the contact of relay 442 and the inner right-hand contact of relay 418 to grounded battery. The release of relay 415 permanently opens the stepping circuit of magnet 417 so that upon release of relay 418, at the termination of the rotation of the distributor SD, the circuit for said stepping magnet will not be closed and the wipers of switch F will, therefore, be maintained in their positions in contact with terminals individual to the toll line.

As soon as the brush arm 801 of the receiving distributor engages segment 826 at the beginning of rotation of said arm, a circuit is established from grounded battery through the ring 827, brush arm 801, segment 826 and winding of relay 810 to ground. This relay energizes and remains in this condition as long as brush arm 801 is in engagement with the segment 826. In energizing, relay 810 connects ground to its contact to prepare a locking circuit for such relays 804 to 809 as are energized by the transmission of the code signals over the common signaling path.

At the same time that the circuit is established for relay 441, brush arm 436 engages the sendin segment 443 to establish a circuit exten ing from positive pole of battery through the normal contact of relay 429, wiper 421, segment 443, brush arm 436, ring 439 and from thence over the previously described path through windings of polar relays 428 and 828 to ground. The polar relay 828 again closes its upper contact. When this impulse is transmitted, brush arm 801 is in engagement with the segments 829 and 830. Inasmuch as the lower contact of polar relay 828 is opened at this time, the battery at the polar relay will not be connected to segment 829 and therefore, a circuit will not be established for the first locking relay 804. The second impulse of the code combination is trans mitted when brush arm 436 engages segment 444 and brush arm 801 engages segment 831. The circuit for this impulse extends from positive pole of battery through the normal contact of relay 430, wiper 422, segment 444, the brush arm 436, segment 439 and then over the conductor P through the windings of polar relays 428 and 828.

This positive impulse again causes the pglarrelay to close its upper contact.

This disconnects battery from the lower contact of the polar relay and hence relay 805 will not be operated through segments 829 and 831 and the brush arm 801. The third impulse to be transmitted is of negative polarity which is connected to the nor mal contact of relay 431, and then to wiper 423 and upon engagement of brush arm 436 with segment 445 and brush arm 801 with the segment 832, this impulse will be transmitted over an obvious path to cause relay 828 to close its lower contact. A circuit is thereupon established extending from grounded battery through the lower contact of relay 828, segment 829, brush arm 801, segment 832 and the right-hand winding of relay 806 to ground. Relay 806 energizes and looks through its left-hand winding and contact to ground at the contact of relay 810. Brush arm 436 then successively engages segments 446 and 447 to transmit: the remaining two impulses of the code combination. These impulses are received at the time the receiving distributor brush arm is in engagement with segments 833 and 834, respectively. The fourth impulse transmitted being of positive polarity, it will be obvious from an understanding of the previous description, that relay 807 will not be energized. The fifth impulse of negative clarity causes the operation of relay 808 w iicli then locks through its left-hand winding and contact to ground at the contact of relay 81.0. Thus in the transmission of the code impulses for the toll line L relays 806 and 808 have been caused to operate and lock. When the brush arm 436 engages segment 448, an impulse of positive polarity Will be transmitted over the path P from the normal contact of relay 449. This positive impulse causes the closure of the upper contact of polar relay 828 and hence no circuit will be established for relay 809 through the segment 835. The battery of negative polarity connected to the segment 450 which is engaged by brush arm 436 sends an impulse over the path P to cause the polar relay 828 to close its lower contact. At this time, brush arm 801 has passed from segments 829 and 835 and hence the closure of the lower contact of relay 828 has no effect upon the receiving apparatus. At the same time the brush arm 436 engages the segment 450 it also makes contact with the segment 451 to establish an obvious energizing circuit for relay 442 which, in opening its contact. breaks the locking circuit for relay 418, which thereupon releases. Before the circuit for relay 442 is established. the relay 441 is released by the brush arm passing from engagement with the segment 440 and relay 441 releases. The removal of battery from the contact of this relay causes the release of relay 317 to open the original energizing circuit for relay 313, but 

